The invention concerns a drive device for a movable furniture part, in particular a drawer, comprising a first and a second lockable ejection device and a synchronizing device for synchronizing the two ejection devices. The synchronizing device comprises a synchronizing rod and a first and second synchronizing element, which can be connected to the synchronizing rod, and a relative movement takes place between the synchronizing elements and the ejection devices during the synchronizing operation. Moreover, the invention concerns an item of furniture comprising a furniture carcass and furniture part movably supported on the furniture carcass and such a drive device.
Generally in the furniture sector, numerous applications are already known with which a synchronizing operation takes place mostly due to the reason to uniformly move the movable furniture part and to not allow a crooked position.
Examples of non-generic synchronizing operations with furniture flaps are known from WO 2011/047396 A1 and WO 2013/040611 A1. Accordingly, actuating devices of flap fittings are synchronized by synchronizing devices. In these cases, each movement of the actuating devices is always transmitted to the other actuating device via the synchronizing rod. No relative movement occurs between the synchronizing rods and the actuating drives during the synchronizing operation. In the latter document, indeed, a so-called touch-latch device for ejecting movable furniture parts is mentioned. However, the movement of the entire actuating devices are always synchronized via the synchronization rods shown in this document and these touch-latch devices are not directly synchronized. Rather, each synchronizing rod is stationarily connected with a corresponding arm of each actuating device. No relative movement takes place between the synchronizing rod and this arm of the respective actuating device.
Further, synchronizing devices are also known with non-generic side stabilizing mechanisms, and an example of this type is EP 2 515 710 B1. These side stabilizing mechanisms serve to synchronize the movements of the drawer rails per se. In this non-generic document, there is no ejection device of any kind whatsoever. A similar device for side stabilization is known from the WO 2012/159136 A1. Herein, it is especially about an overload safety device arranged between shaft parts of a synchronizing rod.
In contrast, the EP 2 429 339 B1 shows a generic prior art device. With this arrangement for locking and ejecting a movable furniture part, the synchronization is reached in that a rotary element in the form of a gear wheel is arranged at an end of a synchronizing rod which rotary element meshes with a gear rack attached to the ejection device. It is disadvantageous in this case that the rotary element has to be arranged in a complicated manner in a holding jack when attaching the synchronizing rod. In doing so, tooth errors may occur between the teeth of the rotary element and the gear rack, whereby the entire synchronizing rod could already be mounted in an undesired oblique manner. Moreover, the gear rack has to be formed quite elaborate with a spring element in order to allow an adaptation of the length of the synchronizing rod to different distances between the ejection devices on both sides. This elaborate telescope configuration of the gear rack is necessary in order to allow in the first place the insertion and subsequent holding of the synchronizing rod on both ejection devices.
Another generic prior art device is disclosed in the not pre-published Austrian Patent Application with the Application number A 785/2013 (AT 514 865 A1). According to this document, a gear wheel arranged on the end of a gear rack meshes with a coupling element (transmission element) also forming the sliding guide track. Also in this case, there are the same disadvantages during insertion and connection as in the previous document.